In current existing photovoltaic systems, two major problems are the amount of engineering design time required for each installation and the amount of labor required to install the photovoltaic panels and equipment. A host of factors, such as location, panel connection configuration, type of panels, type of inverter, use of batteries, etc., contribute to a need for a custom design approach. Manufacturers of photovoltaic panels provide a variety of current, voltage, and power outputs from produced panels. The potential performance from the system is rarely realized because the common method of connecting the panels in a combination of series and parallel configurations produces a system in which the panels with poorest performance degrade the performance of better panels. Once a system is installed, there is no means by which to monitor the individual panels for optimal energy production or failure, nor is there an efficient way to manage decision-making with regard to servicing the system and exchanging energy.
Existing photovoltaic systems make it very difficult to compensate for variations in photovoltaic panels. Additional complexity and expense is added to systems if all of the panels can not be oriented in the same direction. Even when great care is taken to match the photovoltaic panels in a system for optimal performance, a number of events might occur to impede the optimal performance.
One example of this diminution of optimal performance is when the shade from an object crosses a panel or portion of a panel or several panels. A power degradation occurs in the system whereby not only the power loss due to the shading occurs, but the shaded panel also consumes from other non-shaded panels or impedes power from being delivered to the system from other non-shaded panels.
In existing photovoltaic systems, Maximum Power Point Tracking (MPPT) is generally performed on the total connected panel structure rather than on each panel individually. Maximum power from the sum of the total connected panels in the structure is less than the sum of each panel's maximum power produced separately and then summed with other panels in the system. This discrepancy in total power is due to the fact that in practice it is very difficult to find all panels in any system with exactly identical characteristics so that when all panels are coupled together the poorly performing panels degrade the performance of the well performing panels. Manufacturing tolerances for photovoltaic panels are typically 5 percent to 10 percent.
Also in existing systems, because there is such a need to match the characteristics of the panels to each other so closely for optimal performance, it is very difficult to design a system that uses a variety of panels and also a variety of manufacturers of panels. Matching panel characteristics also makes it very hard to add on to the system or replace damaged panels at a later time as well, because the originally used panel may no longer be in production.
Further, existing photovoltaic systems have no way to determine which of the panels are causing the degradation in performance or which panel or component in the system may be the cause of a failure of the system to deliver power. Loss of power may be due, for example, to accumulation of dust, deposits, debris or other items lying on the panel surface, or to temperature differences due to different underlying materials etc., some of which cannot be easily detected. Also, vegetation may be a changeable influence, as for example a shading tree may shift in the wind and hence create unpredictable problems.